US4102195A - Hot spot temperature sensor - Google Patents

Hot spot temperature sensor Download PDF

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Publication number
US4102195A
US4102195A US05/766,819 US76681977A US4102195A US 4102195 A US4102195 A US 4102195A US 76681977 A US76681977 A US 76681977A US 4102195 A US4102195 A US 4102195A
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US
United States
Prior art keywords
acoustic
signal
resonator
waveguide
acoustic waveguide
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US05/766,819
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English (en)
Inventor
John H. Thompson
Stephen Kowalyshyn
Arthur Nelkin
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
ABB Inc USA
Original Assignee
Westinghouse Electric Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Westinghouse Electric Corp filed Critical Westinghouse Electric Corp
Priority to US05/766,819 priority Critical patent/US4102195A/en
Priority to CA000295034A priority patent/CA1118089A/fr
Priority to BE184594A priority patent/BE863262A/xx
Priority to SE7800817A priority patent/SE7800817L/xx
Priority to FR7801938A priority patent/FR2379807A1/fr
Priority to DE19782803225 priority patent/DE2803225A1/de
Priority to ES466584A priority patent/ES466584A1/es
Priority to CH136578A priority patent/CH625881A5/de
Priority to IT41518/78A priority patent/IT1105578B/it
Priority to JP53012039A priority patent/JPS6013452B2/ja
Priority to GB5050/78A priority patent/GB1603141A/en
Application granted granted Critical
Publication of US4102195A publication Critical patent/US4102195A/en
Assigned to ABB POWER T&D COMPANY, INC., A DE CORP. reassignment ABB POWER T&D COMPANY, INC., A DE CORP. ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: WESTINGHOUSE ELECTRIC CORPORATION, A CORP. OF PA.
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01K—MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
    • G01K11/00—Measuring temperature based upon physical or chemical changes not covered by groups G01K3/00, G01K5/00, G01K7/00 or G01K9/00
    • G01K11/22—Measuring temperature based upon physical or chemical changes not covered by groups G01K3/00, G01K5/00, G01K7/00 or G01K9/00 using measurement of acoustic effects
    • G01K11/26—Measuring temperature based upon physical or chemical changes not covered by groups G01K3/00, G01K5/00, G01K7/00 or G01K9/00 using measurement of acoustic effects of resonant frequencies
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N2291/00—Indexing codes associated with group G01N29/00
    • G01N2291/02—Indexing codes associated with the analysed material
    • G01N2291/028—Material parameters
    • G01N2291/02827—Elastic parameters, strength or force
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N2291/00—Indexing codes associated with group G01N29/00
    • G01N2291/02—Indexing codes associated with the analysed material
    • G01N2291/028—Material parameters
    • G01N2291/02881—Temperature

Definitions

  • the invention in general relates to temperature sensing apparatus, and particularly to such apparatus utilizing acoustics.
  • thermistors which may be placed at various desired locations.
  • the themistors provide respective output signals indicative of the localized temperature and these signals are conducted by means of wires to a central location for utilization of the information.
  • the sensor includes a frequency determining element which varies in accordance with the temperature and receiver apparatus at the tank wall, receives the transmitted signal, which is an indication of the temperature in the vicinity of the sensor.
  • Various points in the transformer may be monitored by utilization of various sensors operating at respectively different frequencies.
  • the present invention provides a sensing system particularly useful for high voltage transformers and in which the sensing apparatus within the transformer tank is passive, and without the requirement of any metallic connection to the transformer tank wall.
  • a temperature sensing system which includes an acoustic waveguide and a transmitting means coupled to the waveguide for transmitting an acoustic signal down the waveguide.
  • At least one mechanical resonator is placed at a location, the temperature of which is to be detected, with the resonator being of the type having a resonant frequency which changes with temperature.
  • Means are provided for coupling the acoustic signal in the waveguide to the resonator which will then reflect back up the waveguide any acoustic signal of a frequency equal to the then resonant frequency of the resonator. The reflected back signal is then detected and processed to provide an indication of temperature.
  • a plurality of resonators is provided, each enclosed in its own respective housing and each preferably being of the flexural disc type.
  • a single acoustic waveguide may be provided to pass through the housings of the resonators and acoustic signal transfer between the waveguide and the disc resonator takes place within the housing.
  • a directional coupler arrangement whereby only a reflected signal is conducted to detection apparatus, to the exclusion of a transmitted signal.
  • the arrangement includes means for obtaining an indication of force due to the acoustic energy and of velocity of the acoustic energy.
  • FIG. 1 is a circuit representing the electrical analogy of the electromechanical system of the present invention
  • FIG. 2A is a perspective view of a flexural mode resonator and FIG. 2B is a plan view thereof;
  • FIG. 3 is a block diagram illustrating the temperature sensing system in conjunction with a high voltage transformer
  • FIG. 4 is a view, with a portion broken away, of the resonator of FIG. 2A contained within a housing;
  • FIG. 5 illustrates the frequency spectrum of the signal source of FIG. 3
  • FIG. 6 illustrates frequency signals returned back up the acoustic waveguide of FIG. 3
  • FIG. 7 illustrates a portion of the apparatus of FIG. 3 in more detail
  • FIGS. 8A and 8B are electrical circuit diagrams illustrating the principle of operation of the directional coupler network of FIG. 3;
  • FIG. 9 is a block diagram illustrating the lock-on circuits of FIG. 3 in more detail.
  • FIG. 10 is a cross-sectional view of the acoustic waveguide and its termination
  • FIG. 11 illustrates an alternate signal source
  • FIG. 12 illustrates the signals reflected back up the waveguide, utilizing the signal source of FIG. 11.
  • FIG. 13 illustrates an alternate arrangement of coupling acoustic energy.
  • FIG. 1 serves to basically illustrate the principle of operation of the present electromechanical system, utilizing an electrical analogy.
  • a transmission line 10 includes a plurality of serially arranged LC resonant circuits 12, 13 and 14, each resonant at a respective frequency f 1 , f 2 and f 3 .
  • Resonant circuit 12 presents an extremely high impedance to a signal of frequency f 1 such that all other frequencies continue their transmission down the transmission line while the signal frequency f 1 is reflected back up the transmission line and may be detected by detector 24.
  • resonant circuit 13 will reflect back a signal frequency f 2 while passing all other signals and resonant circuit 14 will reflect back a signal frequency f 3 .
  • the present invention does not use LC resonant circuits but rather mechanical resonators, a preferred example of which is illustrated in FIGS. 2A and 2B.
  • the mechanical resonator is of the flexural mode type which by way of example includes a flexural mode disc 26 made of a high heat conductive metal, such as aluminum or titanium. Integral with the disc 26 is a support means which takes the form of high heat conductive posts 28 and 29 having a lossless bond with the disc 26.
  • disc 26 In its oscillatory flexural mode of operation, disc 26 includes first and second nodal diameters 32 and 33 which divide the disc into four equal quadrants such that the two positive quadrants simultaneously project axially in one direction while the two negative quadrants project in an opposite direction. On a different half cycle the quadrants reverse their directions.
  • Such discs are well known and are further described in U.S. Pat. No. 3,318,152 which is herein incorporated by reference.
  • FIG. 3 a portion of a transformer wall 36 is illustrated with the interior thereof containing transformer equipment generally indicated by the dotted line 38 (windings, etc.) and which equipment is immersed in a transformer oil 40.
  • FIG. 4 illustrates a typical sensor S, of the sensor array of FIG. 3, utilizing a flexural disc resonator as in FIG. 2A.
  • the resonator 26 is protected from the ambient oil by means of a housing 70 (broken away in FIG. 4) and the end portions of which support the posts 28 and 29.
  • Acoustic waveguide 42 is made up of a plurality of nonmetallic fibers 72, one example being glass fibers commonly used in fiber optic applications.
  • the glass fibers 72 are tightly encased in a jacket 74 of some compliant material such as plastic tubing.
  • the housing 70 means are provided for coupling the acoustic signal and the acoustic waveguide to the resonator 26.
  • the glass fibers 72 are connected, such as by means of epoxy, to a plate 76 of a material having a similar acoustic impedance as the glass fiber bundle so as to minimize acoustic mismatch and consequent reflection.
  • a plate 76 of a material having a similar acoustic impedance as the glass fiber bundle so as to minimize acoustic mismatch and consequent reflection.
  • One example of such material is glass.
  • the acoustic waveguide continues with the glass fibers being glued to the other side of plate 76.
  • the acoustic transmission line is coupled to disc 26 by means of a compliant member 78 which effectively decouples the line from the frequencies off resonance.
  • Compliant member 78 may simply be a wire made out of aluminum, and bonded to plate 76 and resonator 26.
  • FIG. 7 illustrates one embodiment of a directional coupler which may be utilized herein.
  • the coupler 52 includes a transmitting transducer 80 which receives the white noise from signal source 50 to provide an acoustic version thereof.
  • One type of transducer which will serve this purpose is the Tonpilz transducer having a head mass, tail mass, and an intermediate motor generator section.
  • the radiating member (the head mass in the case of a Tonpilz) is coupled to a rigid pipe 82, such as aluminum, and which is connected to a force sensor 84, such as a piezoceramic transducer.
  • Rigid pipe 86 connected to the other side of force sensor 84 terminates in a coupler plate 88 and to which is connected the acoustic waveguide 42, such as by having the glass fibers 72 glued thereto.
  • a piezoelectric accelerometer 90 operating in a shear mode to derive a signal proportional to the acceleration of the acoustic waves in pipe section 86.
  • Force sensor 84 in conjunction with amplifier 100 provides a voltage proportional to the force, and is designated k 1 f in FIG. 7.
  • Accelerometer 90 provides an acceleration signal which in conjunction with integrator 94 and amplifier 98 provides a voltage k 2 u, proportional to the acoustic signal velocity.
  • the waveguide arrangement has an acoustic termination equivalent to being terminated in its characteristic impedance so that the gain of the amplifiers may be adjusted such that
  • generator 102 represents the transmitted acoustic signal source, with R being some internal resistance.
  • the circuit includes resistance R o , the characteristic impedance, and further includes a voltage transformer 104 and a current transformer 106 having a resistance R c across the windings thereof.
  • Current transformer 106 and the secondary of voltage transformer 104 are connected in series and to output terminals 108. If e 1 is the voltage of generator 102, then the current flow i is equal to:
  • e 1 is 100 volts and R o and R have the same value of 50 ohms.
  • the voltage produced by current transformer 106 would be 0.25 volts and the total voltage appearing at output terminal 108 is now additive because of the direction change of the current and would be equal to 0.25 + 0.25, or 0.5 volts.
  • R o and R were chosen to be equal.
  • the previous treatment and results are the same, even for different values. For example, suppose that R o was 50 ohms and R was 25 ohms.
  • the voltage of the secondary would be 1/50th of that or 1.333 volts. Since the current sensor has a 1 to 1 ratio, the voltage produced by it would also be 1.33 volts and the difference would still be 0.
  • an integrator circuit 94 is provided to derive from the acceleration signal, a signal which is proportional to velocity.
  • This velocity signal is provided to summation circuit 96 after amplification in amplifier 98 while the force signal from force sensor 84 is provided to summation circuit 96 after amplification in amplifier 100.
  • the signal from amplifier 98 is analogous to voltage e a of FIGS. 8A and 8B while the output of amplifier 100 is analogous to voltage e b .
  • the output of summation circuit 96 may be made substantially zero when accelerometer 90 is accelerated in a first direction by the transmitted signal, with the net result being a multifrequency output signal when the accelerometer is accelerated in an opposite direction by the acoustic energy reflected back up the acoustic waveguide from the various resonators.
  • FIG. 9 illustrates in somewhat more detail a typical lock-on circuit L of FIG. 3.
  • the reflected signal from the various resonators as provided from the summation circuit 96 (FIG. 7) is provided to a bandpass filter 112 for initially filtering the signal so that only a certain predetermined band of frequencies corresponding to a predetermined range of resonant frequency of a particular sensor, is passed.
  • This signal is provided to phase comparator circuit 114, an additional input of which is provided by a voltage controlled oscillator (VCO) 116 operable to provide an output signal. If the VCO output frequency is the same as the frequency of the input signal, then the phase comparator 114 will not provide an output correction signal.
  • VCO voltage controlled oscillator
  • the waveguide is provided with the acoustic termination 44 as illustrated in FIG. 10.
  • the acoustic termination 44 includes a housing member 120 made of a nonmetallic material, such as plastic or ceramic.
  • Tubing 74 of the acoustic waveguide 42 extends through an aperture in housing 120 and is secured thereto with the glass fibers 72 being spread out into the housing which contains an acoustic absorbing material 122, one example being butyl rubber.
  • FIG. 13 shows an alternate embodiment wherein the sensors S 1 to S n are arranged in parallel to simultaneously receive the projected acoustic signal, with each sensor being connected to the projector/receiver 130 by means of a previously described acoustic waveguide with each having a respective acoustic termination as in FIG. 10.

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  • Physics & Mathematics (AREA)
  • Acoustics & Sound (AREA)
  • General Physics & Mathematics (AREA)
  • Measurement Of Mechanical Vibrations Or Ultrasonic Waves (AREA)
  • Measuring Temperature Or Quantity Of Heat (AREA)
  • Arrangements For Transmission Of Measured Signals (AREA)
  • Secondary Cells (AREA)
US05/766,819 1977-02-08 1977-02-08 Hot spot temperature sensor Expired - Lifetime US4102195A (en)

Priority Applications (11)

Application Number Priority Date Filing Date Title
US05/766,819 US4102195A (en) 1977-02-08 1977-02-08 Hot spot temperature sensor
CA000295034A CA1118089A (fr) 1977-02-08 1978-01-16 Sonde captrice de surchauffe ponctuelle
BE184594A BE863262A (fr) 1977-02-08 1978-01-24 Detecteur de temperature d'un point chaud
SE7800817A SE7800817L (sv) 1977-02-08 1978-01-24 Varmfleckstemperaturavkennare
FR7801938A FR2379807A1 (fr) 1977-02-08 1978-01-24 Detecteur de temperature d'un point chaud
DE19782803225 DE2803225A1 (de) 1977-02-08 1978-01-25 Temperaturabtastsystem
ES466584A ES466584A1 (es) 1977-02-08 1978-02-02 Dispositivo detector de temperatura.
CH136578A CH625881A5 (de) 1977-02-08 1978-02-07
IT41518/78A IT1105578B (it) 1977-02-08 1978-02-07 Apparecchiatura di rilevazione di temperatura
JP53012039A JPS6013452B2 (ja) 1977-02-08 1978-02-07 温度検知装置
GB5050/78A GB1603141A (en) 1977-02-08 1978-02-08 Hot spot temperature sensor

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US05/766,819 US4102195A (en) 1977-02-08 1977-02-08 Hot spot temperature sensor

Publications (1)

Publication Number Publication Date
US4102195A true US4102195A (en) 1978-07-25

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ID=25077626

Family Applications (1)

Application Number Title Priority Date Filing Date
US05/766,819 Expired - Lifetime US4102195A (en) 1977-02-08 1977-02-08 Hot spot temperature sensor

Country Status (11)

Country Link
US (1) US4102195A (de)
JP (1) JPS6013452B2 (de)
BE (1) BE863262A (de)
CA (1) CA1118089A (de)
CH (1) CH625881A5 (de)
DE (1) DE2803225A1 (de)
ES (1) ES466584A1 (de)
FR (1) FR2379807A1 (de)
GB (1) GB1603141A (de)
IT (1) IT1105578B (de)
SE (1) SE7800817L (de)

Cited By (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4233843A (en) * 1978-10-30 1980-11-18 Electric Power Research Institute, Inc. Method and means for measuring temperature using acoustical resonators
US4754405A (en) * 1986-02-14 1988-06-28 Qualitrol Corporation Tri-phase electronic temperature controller
US4920522A (en) * 1986-05-05 1990-04-24 Siemens Aktiengesellschaft Method and apparatus for measuring electrical or magnetic fields
US5044769A (en) * 1989-01-14 1991-09-03 Schlumberger Industries Limited Temperature sensors
US6088662A (en) * 1996-12-13 2000-07-11 Seagate Technology, Inc. Thermoelectric temperature sensing system in a computer hard disc drive
US20020150141A1 (en) * 1999-12-10 2002-10-17 Fujitsu Limited Temperature sensor
US20030101822A1 (en) * 2000-03-27 2003-06-05 Eric Atherton Sensor apparatus
WO2012021485A2 (en) 2010-08-12 2012-02-16 Rosemount Inc. Method and apparatus for measuring fluid process variable in a well
CN102928111A (zh) * 2012-11-17 2013-02-13 中科微声（天津）传感技术有限公司 声表面波温度传感器
CN103884415A (zh) * 2014-03-25 2014-06-25 国家电网公司 一种基于无线传感技术的变压器振动监测系统及测试方法
US20140236137A1 (en) * 2013-02-21 2014-08-21 Boston Scientific Scimed, Inc. Ablation catheter system with wireless radio frequency temperature sensor
CN106338336A (zh) * 2016-08-04 2017-01-18 中国南方电网有限责任公司超高压输电公司贵阳局 变压器振动的在线监测系统
WO2021008806A1 (de) * 2019-07-12 2021-01-21 Endress+Hauser Wetzer Gmbh+Co. Kg Temperaturmessgerät
US20210132008A1 (en) * 2017-04-10 2021-05-06 Etegent Technologies Ltd. Distributed active mechanical waveguide sensor driven at multiple frequencies and including frequency-dependent reflectors
CN113721167A (zh) * 2021-09-08 2021-11-30 浙江日新电气有限公司 基于物联网架构的变压器声纹振动检测系统
US11982648B2 (en) 2014-04-09 2024-05-14 Etegent Technologies, Ltd. Active waveguide excitation and compensation

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS57160032A (en) * 1981-03-27 1982-10-02 Mitsubishi Electric Corp Abnormal temperature detecting method of gas insulation apparatus
JPS60209159A (ja) * 1984-04-03 1985-10-21 Nippon Muki Kk ガス検知素子
JP2604181B2 (ja) * 1987-11-02 1997-04-30 東洋通信機株式会社 超音波による非接触温度／圧力検知方法
DE202018100292U1 (de) 2018-01-18 2018-02-02 G & P GmbH Ingenieurbüro für Elektro- und Automatisierungstechnik Temperaturüberwachungsvorrichtung
DE102018102535B3 (de) 2018-02-05 2019-03-28 Elmos Semiconductor Aktiengesellschaft Temperaturmessung mittels der Impedanz eines Ultraschalltransducers

Citations (8)

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Publication number Priority date Publication date Assignee Title
US3318152A (en) * 1963-07-16 1967-05-09 Westinghouse Electric Corp Temperature sensor
US3350942A (en) * 1964-09-15 1967-11-07 Alnor Instr Ultrasonic pyrometer
US3580058A (en) * 1968-05-21 1971-05-25 Panametrics Dual ultrasonic sensors employing a single mode of ultrasonic transmission
US3595069A (en) * 1969-02-14 1971-07-27 Panametrics Ultrasonic sensing system
US3633424A (en) * 1969-09-25 1972-01-11 Panametrics Magnetostrictive ultrasonic transducer
US3636754A (en) * 1970-07-16 1972-01-25 Parametrics Inc Ultrasonic profile measuring apparatus
US3927570A (en) * 1973-03-01 1975-12-23 Asea Ab Means for measuring the temperature in electrical machines
US3999433A (en) * 1974-10-23 1976-12-28 The United States Of America As Represented By The Secretary Of The Air Force Mechanically tuned buffer rod for ultrasonic temperature sensor

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3318152A (en) * 1963-07-16 1967-05-09 Westinghouse Electric Corp Temperature sensor
US3350942A (en) * 1964-09-15 1967-11-07 Alnor Instr Ultrasonic pyrometer
US3580058A (en) * 1968-05-21 1971-05-25 Panametrics Dual ultrasonic sensors employing a single mode of ultrasonic transmission
US3595069A (en) * 1969-02-14 1971-07-27 Panametrics Ultrasonic sensing system
US3633424A (en) * 1969-09-25 1972-01-11 Panametrics Magnetostrictive ultrasonic transducer
US3636754A (en) * 1970-07-16 1972-01-25 Parametrics Inc Ultrasonic profile measuring apparatus
US3927570A (en) * 1973-03-01 1975-12-23 Asea Ab Means for measuring the temperature in electrical machines
US3999433A (en) * 1974-10-23 1976-12-28 The United States Of America As Represented By The Secretary Of The Air Force Mechanically tuned buffer rod for ultrasonic temperature sensor

Cited By (28)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4233843A (en) * 1978-10-30 1980-11-18 Electric Power Research Institute, Inc. Method and means for measuring temperature using acoustical resonators
US4754405A (en) * 1986-02-14 1988-06-28 Qualitrol Corporation Tri-phase electronic temperature controller
US4920522A (en) * 1986-05-05 1990-04-24 Siemens Aktiengesellschaft Method and apparatus for measuring electrical or magnetic fields
EP0246460B1 (de) * 1986-05-05 1991-12-18 Siemens Aktiengesellschaft Verfahren zur Messung elektrischer oder magnetischer Wechselfelder und Anordnung zur Durchführung des Verfahrens
US5044769A (en) * 1989-01-14 1991-09-03 Schlumberger Industries Limited Temperature sensors
US6088662A (en) * 1996-12-13 2000-07-11 Seagate Technology, Inc. Thermoelectric temperature sensing system in a computer hard disc drive
US20020150141A1 (en) * 1999-12-10 2002-10-17 Fujitsu Limited Temperature sensor
US20050089080A1 (en) * 1999-12-10 2005-04-28 Fujitsu Limited Temperature sensor
US7387435B2 (en) 1999-12-10 2008-06-17 Fujitsu Limited Temperature sensor
US20030101822A1 (en) * 2000-03-27 2003-06-05 Eric Atherton Sensor apparatus
US7299678B2 (en) * 2000-03-27 2007-11-27 Baker Hughes Incorporated Sensor apparatus
WO2012021485A2 (en) 2010-08-12 2012-02-16 Rosemount Inc. Method and apparatus for measuring fluid process variable in a well
WO2012021485A3 (en) * 2010-08-12 2012-06-07 Rosemount Inc. Method and apparatus for measuring fluid process variable in a well
US9470084B2 (en) 2010-08-12 2016-10-18 Rosemount Inc. Method and apparatus for measuring fluid process variable in a well
RU2531422C1 (ru) * 2010-08-12 2014-10-20 Роузмаунт Инк. Способ и устройство для измерения технологического параметра текучей среды в скважине
CN102928111B (zh) * 2012-11-17 2014-04-09 中科微声（天津）传感技术有限公司 声表面波温度传感器
CN102928111A (zh) * 2012-11-17 2013-02-13 中科微声（天津）传感技术有限公司 声表面波温度传感器
US20140236137A1 (en) * 2013-02-21 2014-08-21 Boston Scientific Scimed, Inc. Ablation catheter system with wireless radio frequency temperature sensor
US10195467B2 (en) * 2013-02-21 2019-02-05 Boston Scientific Scimed, Inc. Ablation catheter system with wireless radio frequency temperature sensor
CN103884415A (zh) * 2014-03-25 2014-06-25 国家电网公司 一种基于无线传感技术的变压器振动监测系统及测试方法
CN103884415B (zh) * 2014-03-25 2016-01-13 国家电网公司 一种基于无线传感技术的变压器振动监测系统及测试方法
US11982648B2 (en) 2014-04-09 2024-05-14 Etegent Technologies, Ltd. Active waveguide excitation and compensation
CN106338336A (zh) * 2016-08-04 2017-01-18 中国南方电网有限责任公司超高压输电公司贵阳局 变压器振动的在线监测系统
US20210132008A1 (en) * 2017-04-10 2021-05-06 Etegent Technologies Ltd. Distributed active mechanical waveguide sensor driven at multiple frequencies and including frequency-dependent reflectors
US11473981B2 (en) 2017-04-10 2022-10-18 Etegent Technologies Ltd. Damage detection for mechanical waveguide sensor
US11686627B2 (en) * 2017-04-10 2023-06-27 Etegent Technologies Ltd. Distributed active mechanical waveguide sensor driven at multiple frequencies and including frequency-dependent reflectors
WO2021008806A1 (de) * 2019-07-12 2021-01-21 Endress+Hauser Wetzer Gmbh+Co. Kg Temperaturmessgerät
CN113721167A (zh) * 2021-09-08 2021-11-30 浙江日新电气有限公司 基于物联网架构的变压器声纹振动检测系统

Also Published As

Publication number Publication date
SE7800817L (sv) 1978-08-09
FR2379807B1 (de) 1984-10-19
DE2803225A1 (de) 1978-08-10
IT7841518A0 (it) 1978-02-07
IT1105578B (it) 1985-11-04
FR2379807A1 (fr) 1978-09-01
ES466584A1 (es) 1978-10-16
GB1603141A (en) 1981-11-18
JPS5398888A (en) 1978-08-29
CA1118089A (fr) 1982-02-09
BE863262A (fr) 1978-07-24
CH625881A5 (de) 1981-10-15
JPS6013452B2 (ja) 1985-04-08

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